Management of an Appendiceal Mass - Approach to acute presentation of appendiceal neoplasms Dr. Claudia LY WONG, Department of Surgery, Kwong Wah Hospital Joint Hospital Surgical Grand Round Presentation, Princess Margaret Hospital, April 20, 2013
Case Scenario M/42; unremarkable past health Periumbilical pain shifted to right lower quadrant for two days Associated with nausea and subjective account of fever Physical examination: Temperature 38.9oC; Stable hemodynamics Localized tenderness and fullness over right lower quadrant
Suspected Appendiceal Neoplasm A CT scan was performed Complex cystic appendix with thickened wall Suspicious of underlying neoplasm Tachycardia, persistent tenderness and pyrexia despite antibiotic therapy
Introduction 1. Overview of commonest appendiceal neoplasms and mucocele 2. Management of acutely presenting appendiceal mass suspicious of underlying neoplasm
Differential diagnoses Neoplasms of vermiform appendix Connor et al. (1998) Appendiceal tumors: retrospective clinicopathologic analysis of appendiceal tumors from 7,970 appendectomies. Secondaries from urogenital tract (ovaries), large bowel, lung and breast Others (rare): ganglioneuroma, pheochromocytoma, mesenchymal tumors, Kaposi sarcoma Appendiceal mucocele
Appendiceal Neoplasms & Mucoceles
Appendiceal Carcinoid Neuroendocrine origin, arise from primitive stem cell Classified according to location of primitive gut Deep in mucosa for intestinal carcinoids Appendix is the commonest site for carcinoid tumor Carcinoid is the commonest primary neoplasm of the appendix
Appendiceal Carcinoid 0.3-0.9% appendicectomies; usually asymptomatic, incidental finding in appendicitis Most affect distal 1/3; invade wall Symptoms occur with metastasis (rare) Liver metastases are rare; Lymphatic spread as 1* route Worse outcome with large size (>1.5-2cm), goblet cell carcinoid (adenocarcinoid)
Intestinal and Mucinous Neoplasms Benign: adenomas, cystoadenomas Malignant: adeno/ cystoadenocarcinomas More goblet cells in appendix than in colon -> majority of neoplasms are mucinous in nature
Cystoadenocarcinoma (mucinous) Appendiceal carcinomas: 90% mucinous (vs intestinal type) Mucinous subtype: Tip or along lumen Mucocele formation Dissemination to peritoneal space, pseudomyxoma peritonei
Adenocarcinomas (intestinal) Appendiceal carcinomas: 10% intestinal type Intestinal subtype: Appendiceal orifice Lymph node spread
Appendiceal Mucoceles A rare but not entirely separate entity Morphological description Histological Subtypes of Appendiceal Mucoceles Cystic dilatation of appendix caused by accumulation of mucus secretion 10% 0.2-0.4% appendicetomy specimens 18% Course and prognosis depends on histological subtype 52% Luca et al. Surgical Management of Appendiceal Mucocele. Arch Surg. 2003; 138: 585-590 Often asymptomatic (51%); abdominal pain (27%), mass (16%), weight loss (10%), appendicitis (8%) 20% In the presence of pseudomyxoma peritonei or mucinous dissemination, 80-90% are malignant Mucinous cystadenomas Mucosal hyperplasia Simple mucoceles/retention cysts Mucinous cystadenocarcinomas
Management of Suspected Appendiceal Neoplasms
1. Emergency Surgery Detailed laparoscopy Macroscopic features of index lesion: Location on appendix, caecal involvement Mesoappendiceal involvement Size of lesion (>2cm) Any mucinous dissemination or spontaneous perforation Any other primary lesion (appendiceal secondary?)
1. Emergency Surgery Pathology and histological characteristics of appendiceal tumor determine extent of definitive surgical resection and need of prophylactic lymph node removal Achieve macroscopic resection margin, including mesoappenix Appendicectomy, ileocaectomy, right hemicolectomy? Avoid trauma or rupture during removal Use of endobag; retrieval from midline (facilitate port site removal if necessary) Thorough peritoneal washout if mucinous dissemination Wait for histology result and consider second operation
2. Further Investigations? Non-carcinoid neoplasms: Carcinoid neoplasms: Tumor markers: CA-125, CA-19-9, CEA (in mucinous peritoneal carcinomatosis) Serotonin metabolite 5-HIAA 24- hour urine sample; chromogranin A (lower specificity) Computed tomography: look for distant metastasis, serve as baseline for disease monitoring Surveillance colonoscopy: ALL appendiceal neoplasms are associated with synchronous or metachronous colonic neoplasms Nuclear imaging: OctreoScan (somatostatin analogue) (80% carcinoid with somatostatin receptor); metaiodobenzylguanidine (MIBG) scan PET scan: based on metabolism of trytophan
3. When to Consider Completion Right Hemicolectomy? Prophylactic resection for occult lymph node metastasis Based on histolopathological findings of initial resection Carcinoid: right hemicolectomy is recommended for lesions >2cm Increased probability of nodal involvement 30% (<0.1% for lesions <1cm) (Sutton et al); controversy for lesions between 1-2cm Involvement of mesoappendix, atypical microscopic foci, mitotic count of 2 or more per HPF, goblet cell type
3. When to Consider Completion Right Hemicolectomy? Adenocarcinoma: tradition approach is to offer right hemicolectomy Much higher incidence of lymph node metastasis in adenocarcinoma (66.7%) than mucinous carinoma (4.2%) (Gonazlex Moreno et al) >2cm, poor differentiation, lymphovascular permeation, submucosal invasion Mucinous adenocarcinoma: more selective approach to right hemicolectomy Median survival similar for those with or without lymph node involvement (28 vs 26 months) (Kiran at al)
3. When to Consider Completion Right Hemicolectomy? Presence of mucinous dissemination: Low grade mucinous neoplasms: no recurrence in 6-year follow-up vs those with extra-appendiceal spread: 45% 5-year survival Radical resection does not alter prognosis of mucinous neoplasm with peritoneal dissemination Not advisable unless intraperitoneal chemotherapy and cytoreductive surgery
4. Adjunctive Therapy? Carcinoid neoplasms: Metastatic carcinoid: 5-fluorouracil (5-FU) and leucovorin Hepatic metastases: resection/ablation, interferon, hepatic artery embolization (>50% involvement), long-acting somatostatin analogue (carcinoid syndrome) Non-carcinoid neoplasms: NO controlled study Same regime as colonic adenocarcinoma Poor tumor response in case of peritoneal dissemination; intraperitoneal heated chemotherapy
Management Algorithm for Suspected Appendiceal Neoplasm Acute appendiceal mass (suspicious CT findings) Failed antibotic therapy Emergency resection (macroscopic margin + mesoappendix) Histology proven neoplasm Further investigations (tumor markers, imaging, colonoscopy) Determine need for completion right hemicolectomy Specialist centre referral/oncologist referral/surveillance
Conclusion Appendiceal neoplasms are rare but often present as acute appendicitis Most common lesions are carcinoid neoplasms & adenoma/ adenocarcinoma of intestinal and mucinous types Initial treatment without prior histological diagnosis proves a challenge Achieve macroscopic margin with careful specimen handling Option of a planned second operation is available Follow up management including surveillance colonoscopy is necessary
References Walters et al. Treatment of appendiceal adenocarcinoma in the United States: penetration and outcomes of current guidelines. Am Surg. 74(11):1066-8, 2008 Nov Murphy et al. Management of an Unexpected Appendiceal Neoplasm. British Journal of Surgery 2006; 93: 783 792 Groth et al. Appendiceal carcinoid tumors: Predictors of lymph node metastasis and the impact of right hemicolectomy on survival. J Surg Oncol. 2011 Jan 1;103(1):39-45. Goede, A. C., Caplin, M. E. and Winslet, M. C. (2003), Carcinoid tumour of the appendix. Br J Surg, 90: 1317 1322 Connor SJ, Hanna GB, Frizelle FA. Appendiceal tumors: retrospective clinicopathologic analysis of appendiceal tumors from 7,970 appendectomies. Dis Colon Rectum. 1998 Jan;41(1):75-80. Whitefield et al. Surgical management of primary appendiceal malignancy. Colorectal Dis 2012; 14, 1507-1511 Luca et al. Surgical Management of Appendiceal Mucocele. Arch Surg. 2003; 138: 585-590